National Repository of Grey Literature 61 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
Use of biomarkers for assessing environmental pollution by platinum group metals
Nedvědická, Lucie ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This diploma thesis in the theoretical part analyses the characteristic feature of individual platinum group elements, their toxicity, anthropogenic sources and the presence of platinum group elements in the environment of the Czech Republic. In addition, there are specified types of bioindicators focusing mainly on lichens, mosses and needles. There are described individual bioindication techniques and pre-treatment of samples for platinum metals determination in bioindicators. The subject of the experimental part is to verify the sorption efficiency and ability of platinum and palladium using the SPE method and to determine the actual platinum metal contamination in selected localities in the city of Brno. There was also the additionally subject to verify the sorption potential of selected bioindicators and determination of the environmental pollution by platinum metals using the bag technique. In the experimental part, the bioindicators of moss Pleurozium schreberi, lichen Xanthoria parietina, lichen Flavoparmelia caperata and needles Pinus nigra were used.
Study of the influence of nanoparticles on water properties
Šram, Matěj ; Komendová, Renata (referee) ; Řezáčová, Veronika (advisor)
This work deals with the study of the influence of platinum nanoparticles with a size of 3 nm on the properties of water in a porous system. SiO2 with a defined pore size was used as a porous system, which can simulate the mineral component of the soil. The theoretical part deals with the properties of free and porous water and the impact of nanoparticles on the environment. In the experimental part, the properties of free water, water in the porous system and the influence of the presence of platinum nanoparticles on these systems are investigated using differential scanning calorimetry (DSC). The observed processes were melting, solidification and evaporation, and derived quantities such as crystallization and melting point.
Determination of platinum group metals in great urban agglomerations
Ježek, Stanislav ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
The aim of this thesis is the actual elaboration literature search concerning the issue of platinum group metals in the environment, determination of platinum and palladium in great urban agglomerations. It includes chemical and physical properties, occurrence and platinum and palladium cycle in the environment. It also contains methods for extraction and determination of platinum and palladium.
The use of SPE methods for determination of ultratrace concentrations of platinum metals in environmental matrices
Ježek, Stanislav ; Zlámalová Gargošová, Helena (referee) ; Gregor, Tomáš (referee) ; Komendová, Renata (advisor)
This dissertation is focused on the study of sorption techniques for the determination of platinum and palladium on modified solid sorbents and ion exchangers. The final determination was made using atomic absorption spectrometry with electrothermal atomization (ET-AAS). Six modified sorbents were selected for the sorption study. Four modified non-polar silica gels were studied and two sorbents were based on styrene divinylbenzene copolymer. Furthermore, three cation exchange resins and three anion exchange resins were studied. The sorption efficiency of platinum and palladium was studied with modified sorbents and anion exchange resins. Furthermore, the influence of interfering elements (Fe, Cu, Zn, Pb, K, Na, Ca and Mg). Another parameter for evaluating the effectiveness of sorbents is the volume of the elution mixture required for effective elution of platinum and palladium from the sorbents. Based on the results, a sorbent was selected for the preconcentration of platinum and palladium from real environmental samples from the environment. The study of the concentration of platinum and palladium in environmental components is divided into two parts. The first part compares two cities with different sizes and vehicle concentrations. It is a regional capital in the Czech Republic – Jihlava and the capital of Austria – Vienna. For soil matrix sampling, locations near frequent traffic junctions were selected. In Jihlava, the concentration of platinum ranged from 16.93 to 38.72 ng.g-1 and for palladium from 2.705 to 8.452 ng.g-1. In Vienna, the detected concentrations were higher. Platinum concentrations ranged from 39.22 ng.g-1 to 159.2 ng.g-1 and for palladium from 18.45 ng.g-1 to 98.21 ng.g-1. The second part was focused on the busiest traffic junction in the Czech Republic - the D1 highway, focusing on the section near the Švihov water reservoir, which serves as one of the main sources of drinking water for the capital of the Czech Republic - Prague. Rain retention tanks - "lapolas" - are installed in this section. A soil sample was always taken in the vicinity of these lapolas, and from the lapolas the sediment in the reservoir and settled water at the outlet from the reservoir. These rain retention tanks proved to be suitable places for monitoring pollutants from automobile traffic.
Determination of platinum group metals in soils the city of Brno
Pavlíčková, Ivana ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
The diploma thesis focuses on identifying the presence of platinum in soil samples by absorption spectroscopy. The work is divided into two parts, the theoretical part is focused on the occurrence and behavior of platinum in the environment, the fundamental chemical and physical properties of platinum, its importance in catalytic converters in cars, on solid phase extraction method and the method for the determination of atomic absorption spectrometry. The second part is the practical part, focused on the determination of the platinum amount in the soil samples in the city of Brno.
The significance of platinum in the environment
Brestovská, Marta ; Holubová, Zuzana (referee) ; Sommer, Lumír (advisor)
This bachelor thesis deals with monitoring of individual platinum compounds in the environment (water, soil, air) and is also reviewing methods used for their analysis. The no less important determination of platinum in tissues and body fluids, when the platinum is used in form of a cisplatin as an anticancer drug, is also mentioned. Afterwards the anticancer drug itself or its derivatives and metabolites on the base of platinum complexes in clinical sample (urine, plasma) are determined. Mainly the ICP-AES, ICP-MS, ETA-AAS, HPLC methods are highlighted from the methods used for the determination of Pt. The on-line connection between some of these methods such as ICP-MS with HPLC or ICP-AES with HPLC seems to be useful. The spectrofotometric methods using organic and inorganic agents can also be used for the determination of platinum. These methods are mentioned here rather marginally, just for completeness. In terms of practical use they are difficultly reproducible and not very sensitive. The hydrolysis of platinum metals to form insoluble hydrated oxides makes also the determination difficult.
Investments of the Automotive Industry in Precious Metals as Strategic Materials
Dvořáček, Martin ; Plíhal, Tomáš (referee) ; Rejnuš, Oldřich (advisor)
The subject of the thesis is the investment recommendations of companies operating in the automotive industry to purchase strategic raw materials, such as in particular platinum, palladium and rhodium. Thesis include a theoretical description of the topic, respectively certain forms of hedging, instruments used to hedge and brief characteristics of precious metals. Analytical and proposed section of the thesis contains specific methods, procedures and its own approach used to meet the global target of thesis.
Platinum group elements in waste and surface waters
Novotný, Matěj ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
This assignment provides a detailed description of platinum metals, their occurrence in surface and waste water and their determination options. Currently, platinum metals are widely used in the automotive industry as a part of a catalyst, as well as in medicine and jewelery. Release of these metals in pure form and the form of oxides leads to their subsequent accumulation, which directly affects fauna and flora. Due to that, the living conditions and health status of some organisms are petting worse.
Application of preconcentration/separation techniques for the determination of platinum in the environment by atomic spectrometry
Kosárová, Hedvika ; Čelechovská, Olga (referee) ; Komendová, Renata (advisor)
This thesis deals with optimization of conditions for the determination of platinum by electrothermal atomic absorption spectrometry. The theoretical part describes the occurrence of platinum in different part of the environment, its physical and chemical properties, transport and bioavailability. There is also evaluated appropriate method for determination and preconcentration of platinum. The experimental part describes advance of optimize the measurement conditions for ETA-AAS, further is describes optimization of condition for SPE and work with real samples on which are applied this conditions.
The study of behavior of platinum nanoparticles in environmental compartments
Berka, Michal ; Řezáčová, Veronika (referee) ; Komendová, Renata (advisor)
Platinum nanoparticles pose a risk to environmental compartments. The aim of this diploma thesis is to conduct research on the influence of platinum nanoparticles in a wide range of concentrations on soil properties at different humidities. Specifically, it is about influencing the stability of water molecular bridges, the content of aliphatic crystallites, the retention capacity of water in the soil and the strength of water binding. Furthermore, the amount of nanoparticles sorbed on the soil was also measured. These indicators give us more information about the influence of platinum nanoparticles on evapotranspiration and soil deterioration. Methods of thermal analysis (differential scanning calorimetry) and optical methods (atomic absorption spectrometry) were used for these researches. The theoretical part of the work is devoted to a comprehensive introduction to platinum and its nanoparticles, as well as aqueous molecular bridges. It has been found that 200 nm platinum nanoparticles affect the strength of aqueous molecular bridges, have no effect on aliphatic crystallite content, have minimal effect on soil water retention, and that the water bond strength decreases due to platinum nanoparticles at high relative humidity. With 200 nm platinum nanoparticles, complete adsorption to soil occurs over the entire concentration range. With 3 nm nanoparticles, the soil is supersaturated at higher concentrations and larger amounts are not adsorbed. The results show that the larger the size of the platinum nanoparticles, the lower the negative effect on evapotranspiration and soil function itself.

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